Abusing CT log is unethical.
For practical purposes DKIM signatures in emails would do the trick.
Write an email to yourself, or to someone you trust, its DKIM will include the timestamp and it can be verified publicly.
For practical purposes DKIM signatures in emails would do the trick.
Write an email to yourself, or to someone you trust, its DKIM will include the timestamp and it can be verified publicly.
The fact that it allows to verify the authenticity of leaked emails is only a small and not necessarily negative side-effect.